Boring-chuck.



L. A'i NILSSON.

. BORING CHUCK. APPLIOATION IILEI? NOV. 10 1902.

' Inventor.

Amy.

PATENTED MAR. 26, 1907. I

@MW I UNITED S T S PATENT OFFICE; I

'LARS'AXEL ,NILTSSON, or K'Ar aiNEno M, SWEDEN.

eon!auc-r-o -ihex.-

To alt whom it may concern. 7

Be it known that I, LABS AxEL NrLssoN, draftsman, a subject of the King of Sweden, and a resident of Katrineholm, Sweden, have invented new and useful Improvements ina Boring-Ohuck; and I do declare the following to be afull', clear, and exact description of the invention, such as will enable others 1 skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in boring-chucks of the class in which gripping members movably arranged in the body portion of the chuck and adapted to hold the shank of the tool are\ brought into operative position by means of an angularly displaca able sleeve carried by the said body portion and having eccentric surfaces on its inner side adapted. to engage the tool gripping members. H p

The object of the invention is to provide a chuck of this kind which will center and at the same time grip the tool with a force that increases in the same ratio or greater than the work or power transmitted through the chuck to the tool, thus permitting the transmission of any amount of power through the chuck to the tool without the employment of tively to the chuckbody in a direction to' cause the pressure between the tool-gripping members and the tool, as well as between the tool-grip in members and the-friction-sprfaces of t re s eeve, to become increased, owing to the fact that thetangential componentof.

the pressure at the points of contact between the tool-gripping members and'the frictionsurfaces never exceeds the tangential component of the frictional force at thesanie points of contact. These two tangentlal components are opposed to each other, and as the latter tends to angularly dis lace the sleeve,

andwith it the friction-s n aces, in a direc-,

tion to increase the gripping force a positive Specification of Letters Patent. Application filed N ovcmberlflylflofll Serial No. 130,785.

the body Patented Marchd26, 1907.

grip, as well as anexact alinement of the tool, isinsured.) f

In the accompanying drawings I have illustrated a chuck embodying'my invention. Figure 1 is a sectional elevation of the line A B of Fig.1. Fig; 3 is a side elevation of the chuck-body shown separately. 4

is a plan of, a divided ring .for connecting thesleeve to the chuck-body, asfihereinafter exwith the tool-gripping membersre 1 moved. Fig.2 is a horizontal section on the plained. Figs. 5 and 6 are an elevation and end View of a preferable form of on? 0f the tool-gripping members detached. "Fig. 7 is a'fragmentary sectional elevation showing a modification. Fig; 8 is a crosssection on the line'C'D of Fig. 7. I e The chuck consists of a central body ortion is, the forward or inner part of whic is hollow and formed with seats h for the gripping member 11, which in the example 'illustrated comprise rollers or balls. I In the former case the seats are formed by longitudinal slots oropenings. In thelatter case;

horizontal rows or openings could be made in place of'the longitudinal slots. The slots extend from the exterior to the interior of portion, thus permitting the gripping mem ers to projectfrom the said slots internally aswell as externally. The rear or outer part of the chuck-body is formed with a head 0, which is provided with the ordinary opening d for the reoeption'of the spindle'of the boring-machine or othertool to which the chuck is to be applied.

a is the angularlydisplaceable sleeve having the internal friction-surfaces-m, with."

which the gripping members cooperate. As herein shown, thesurfaces m are formed in a separate sleeve 1, which maybe sunk in or ot erwise firmly anchored tothe sleeve a in any desired manner. The said sleeve has its bearing on the head 0 of th'chrick-body and is free to turn thereon, but is otherwise kept in position relatively to the chuck-bod by means of a liivided ring 9, (composed 0 one or several parts), contained m an annular channel e, formed between the head and a ioo flange d of the chuck-body and kept'in place 'byscr'ews'f; v

In order to fit a boring or similartool in' the chuck, the stem of said tool is' inserted into place through the opening I), provided in the sleeve a, the' said sleeve having been first angularly displaced on the chuck-body by .hand in opposition to either the friction of the ring 9 or the resistance of a spring 0, which is anchored to a pin p, secured to part 76. i The gripping members i are thus enabled to move radially. outward into the deeper portions or bases of the internal friction-surfaces mand to thereby separate in the act of introducing the stem of the boring-tool through thesaid opening I). The stem of the borin -tool having been thus inserted, the said sleeve a is turned back, toward itsoriginal position either by hand or by the reaction of the s ring 0, whereby thegripping memhere will be pressed by the higher portions or crests of the friction-surfaces against the shank of the toolwith a certain force which, if the spring 0 be used, will depend upon the strength of the latter. I

In transmitting the driving power through the chuck to the boring-tool the chuckbody and the gripping members seated in the same are (at the moment of applying the power) first caused to turn relatively to the shank of the boring-tool. Then the friction between the shank of the boring-tool and the gripping members tends to rotate the latter in an opposite direction to that in which the boringtool turns. This tendency of'said gripping members to rotate in contact with the frictioh-surfaces m imparts to the sleeve a a tendency to turn' relatively to the chuckbody in a direction to cause-the friction-surfaces to become firmly wedged against the gripping members. The pressure between the gripping members and the shank of the boring-tool is thus increased until the friction corresponds to-the transmitted power. The boring-tool is thus held firmly in place, but in such a manner that it can be very readily di's enga ed from the chuck when necessary by mere y angularly displacing the sleeve a in the opposite. direction by hand.

The chief advantages derived from my im- 'pIOVQCl chuck are that the tool can be quickly changed withoutthe use of any special key or wrench and even without stopping the machine, that no special means or care is necessary to- 'et the tool in exact alinement, that the shank of-the tool does not need to be provided with grooves, tapers, or projections, and that a number of different sizes of tools can be used withoneand the same chuck.

What I claim, and desire to secure by LettersPatent of'the United States, is-

1. In a chuck, the combination of a body having an axial bore for the reception fof a tool shank or the like, and provided with a radial o ening,-a radially-movable tool-gripping rol ier seated in said op'ening,.a sleeve.v embracing said body and. rotatable thereon and provided with an internal cam constructed and arranged to bear against said toolgripping roller and force it inward when rotated.

2. In a chuck, the combination of a body and a surrounding sleev'e, said body and sleeve being relatively rotatable, said-body having an axial tool-opening and a radial opening, a rolling gripping device radially movable in the radial opening of said body,

said surrounding sleeve provided with a camnally against the tool and externally against the sleeve, and angularlydisposed cam-surfaces on said sleeve for the rollers to bear against, the movement of the rollers about their axes when power is transmitted through the chuck to the tool displacing'the .sleeve in a direction to cause the cam-surfaces to automatically exert on the rollers and the tool an inward pressure which increases with the power.

4. In a chuck, the combination with a hol low body portion having longitudinal slots therein, a sleeve, angularly displaceable thereon, a series of radially; displaoeable tool-gripping rollers situated in said slots of the body portion and adapted to bear inter?- nally againstthe tool and externally against.

the sleeve, eccentric friction-surfaces on said sleeve for the rollers to bear against, and. means for'normally keeping the sleeve in a position in which the crests of the eccentric friction-surfaces bear against the rollers and enable the latter, intending to roll about their axes when power istransmitted through thechuck to the tool, to ang'ularly displace the sleeve in a direction to cause the eccen-' .tric fraction-surfaces to automatically exert on the rollers and the tool; aninward pressure which incre'ases with the power.

5. In-a chuck, the combinationwith a hol low body portion having longitudinal slots at its innerend, a sleeve detachably connected wit'hsaid portion and angularly displaceable thereon, a series of radially-displaceabletool- 'gripping' rollers, situated in said slots of the body portion'and adapted. to bear internally ,against thetool and externally against the sleeve, eccentric friction-surfaces'on said sleeve for the rollers ,to'bear against, and a spring fornormally keeping the. sleeve in a ositio'nie 'ivhichthe crests of the eccentric iction-surfaces bear againstthe rollers and enable the latter, in tending to relL-ebcut In testimony whereof I eflixmy signature their axes when power is transmitted through in presence of two witnesses. the chuck to the tool, to angularly displace LABS L NILSSON the sleeve. in a direction to cause the eccentric friction-surfaces to automatically exert Witnesses":

on the rollers andthe tool an inward pressure CHAS. FREDBOBG,

which increases with the power. ERNST NAIDsmTH. 

